Filamentous fungi, namely molds, are known to have various functions, and for example, plant diseases are known to be caused by pathogenic filamentous fungi. Pathogenic filamentous fungi are the cause of diseases such as damping-off, root rot, leaf rot and wilt in agricultural products including many vegetables such as cabbage, cucumber, tomato, eggplant and rape leaf and rice plants, as well as in flowers, trees, turf and others. As such pathogenic filamentous fungi, those belonging to the genus Rhizoctonia, the genus Fusarium, the genus Pythium, the genus Trichoderma and the genus Sclerotium are well known.
Examples of a method of controlling plant disease which is effective against such pathogenic filamentous fungi include those plant disease control agents using a microorganism, specifically a filamentous fungus (for example, WO 97/31521 and WO 2006/085567). It is generally known that the suitable growth conditions are different between bacteria and filamentous fungi. Therefore, plant disease control agents utilizing, instead of a bacterium, a functional filamentous fungus capable of demonstrating plant disease-controlling function under the suitable growth condition for a pathogenic filamentous fungus are expected to have a more superior effect compared to those plant disease control agents utilizing bacteria. Among such plant disease control agents, one which utilizes a filamentous fungus belonging to the family Coprinaceae has a superior function (see WO 2006/085567).
By the way, in order to utilize such a functional filamentous fungus as a plant disease control agent, it is necessary that the functional filamentous fungus be made to exist in a soil or compost at an appropriate density so as to demonstrate an appropriate plant disease-controlling function, and that the functional filamentous fungus maintains this function.
In order to conveniently utilize a prescribed function of a functional filamentous fungus, a product containing the functional filamentous fungus is produced in some cases by inoculating the functional filamentous fungus to a soil, compost, solid medium or immobilization carrier. When such a functional filamentous fungus-containing product is prepared, it is indispensable to appropriately monitor the concentration of the functional filamentous fungus during the process of production, storage, transport or the like.
In recent years, techniques which detect and identify bacteria using a molecular biological means have been developed.
For example, Japanese Patent Application Laid-Open (JP-A) No. 2007-268471 provides a method for detecting methane-producing bacteria and acid-producing bacteria relating to methanogenesis in sludge for methane fermentation treatment, such as organic waste and waste water and evaluating the activity of the bacteria, thereby disclosing a suitable operation management index of a methane fermentation apparatus and a process control method. This method utilizes a method of exhaustively and quantitatively detecting Eubacteria group to which acid-producing bacteria belong or methanogen group having methane-producing ability, and includes quantitatively detecting and monitoring over time the DNA and RNA concentrations using a PCR method.
Further, JP-A No. 2007-174973 discloses a technique whereby DNA contained in a sample of, for example, agricultural product (crops and vegetables), livestock product (meat), fishery product (fish and shellfish), hair, body fluid or microorganism can be amplified and analyzed highly accurately, promptly and simply, as well as at a low cost. This method includes the step of amplifying the DNA in a sample by PCR, which step is conducted by multiplexing using SSR primer pair.
However, in addition to a desired functional filamentous fungus, a variety of filamentous fungi and bacteria are present in a soil and compost. Monitoring of only a specific functional filamentous fungus in such a soil or compost requires a detection method which shows very high specificity. Also required is an evaluation method which appropriately evaluates a product containing the functional filamentous fungus obtained by inoculation of the functional filamentous fungus.